Topic: Tube bender keeps kinking the tube. Why????

[alwayzbroken]

I am in the process of bending a front bumper with I think a JD2 Tube bender. It says JD squared on top. We have used the bender many times with no problems. Another friend who is a very experieced tube bender couldn't figure it out either.

We are using a 1-3/4" 5 1/2" die and the bender is fitted with a electric hydraulic pump. The tube is HREW .095 wall. The first bend we made out of a scrap piece that was laying around with the same wall thickness did not kink at 90 degrees. We took a brand new stick and bent to the exact same angle and it kinked like an exhaust pipe. WTF?? We have messed around with it and found that it starts to kink at 45 degrees. Could we have gotten a bad stick of tube? Is that possible? Any help would be appreciated. Thanks.

[Willy Mammoth]

That is possible, the pipe could be hard, but I doubt it.

Does the pipe fit snug in the dies and is it lubed up so the follower will slide on it?

[KYOTA]

I would say it is that the tube is .095 (thin) and has less resistance to kinking with that size of tube OD. If it were smaller tube say 1" OD and .095 it would be fine. JD2 and Pro-Tools have a recommended material thickness with each die. Your 1 3/4" x 5.5 clr die calls for a minimum of .095 tube thickness. Throw a piece of .120 in there and I bet you'll be ok.

 http://www.jd2.com/

100178 M3B Round Tube Die Set - 1/2 " (2.25-180) .035" $115.00 *
100179 M3B Round Tube Die Set - 1/2 " (3-180) .035" $135.00 *
100180 M3B Round Tube Die Set - 5/8" (2.25-180) .049" $115.00 *
100181 M3B Round Tube Die Set - 5/8" (3-180) .049" $135.00   
100182 M3B Round Tube Die Set - 3/4" (2.25-180) .058" $115.00 *
100183 M3B Round Tube Die Set - 3/4" (3-180) .058" $135.00 *
100186 M3B Round Tube Die Set - 3/4" (4.5-180) .058" $195.00   
100188 M3B Round Tube Die Set - 3/4" (5.5-180) .058" $220.00   
100189 M3B Round Tube Die Set - 7/8" (3-180) .058" $140.00 *
100191 M3B Round Tube Die Set - 7/8" (4.5-180) .058" $195.00   
100193 M3B Round Tube Die Set - 7/8" (5.5-180) .058" $220.00   
100194 M3B Round Tube Die Set - 1" (3-180) .058" $145.00 *
100195 M3B Round Tube Die Set - 1" (3.5-180) .058" $175.00 *
100197 M3B Round Tube Die Set - 1" (4.5-180) .058" $205.00 *
100199 M3B Round Tube Die Set - 1" (5.5-180) .058" $230.00   
100200 M3B Round Tube Die Set - 1 1/8" (3.5-180) .083" $175.00 *
100202 M3B Round Tube Die Set - 1 1/8" (4.5-180) .058" $215.00 *
100204 M3B Round Tube Die Set - 1 1/8" (5.5-180) .058" $240.00   
100206 M3B Round Tube Die Set - 1 1/8" (6.5-180) .058" $250.00   
100207 M3B Round Tube Die Set - 1 1/4" (3.5-180) .083" $175.00   
100209 M3B Round Tube Die Set - 1 1/4" (4.5-180) .058" $215.00 *
100211 M3B Round Tube Die Set - 1 1/4" (5.5-180) .058" $240.00   
100213 M3B Round Tube Die Set - 1 1/4" (6.5-180) .058" $250.00   
100215 M3B Round Tube Die Set - 1 3/8" (4.5-180) .095" $225.00 *
100217 M3B Round Tube Die Set - 1 3/8" (5.5-180) .065" $240.00 *
100219 M3B Round Tube Die Set - 1 3/8" (6.5-180) .065" $250.00   
100223 M3B Round Tube Die Set - 1 1/2" (4.5-180) .095" $225.00 *
100226 M3B Round Tube Die Set - 1 1/2" (5.5-180) .083" $240.00 *
100228 M3B Round Tube Die Set - 1 1/2" (6.5-180) .058" $250.00 *
100234 M3B Round Tube Die Set - 1 5/8" (5.5-180) .083" $250.00 *
100236 M3B Round Tube Die Set - 1 5/8" (6.5-180) .083" $260.00 *
100240 M3B Round Tube Die Set - 1 3/4" (5.5-180) .095" $260.00 *
100242 M3B Round Tube Die Set - 1 3/4" (6.5-180) .083" $275.00 *
100246 M3B Round Tube Die Set - 1 7/8" (6.5-180) .095" $295.00 *
100249 M3B Round Tube Die Set - 2" (6.5-180) .095" $295.00 *

[alwayzbroken [OP]]

That is possible, the pipe could be hard, but I doubt it.

Does the pipe fit snug in the dies and is it lubed up so the follower will slide on it?

The tube fits well and we were lubing the hell out of it with motor oil then tried Dexron III and no difference.

I would say it is that the tube is .095 (thin) and has less resistance to kinking with that size of tube OD. If it were smaller tube say 1" OD and .095 it would be fine. JD2 and Pro-Tools have a recommended material thickness with each die. Your 1 3/4" x 5.5 clr die calls for a minimum of .095 tube thickness. Throw a piece of .120 in there and I bet you'll be ok.

 http://www.jd2.com/

100178 M3B Round Tube Die Set - 1/2 " (2.25-180) .035" $115.00 *
100179 M3B Round Tube Die Set - 1/2 " (3-180) .035" $135.00 *
100180 M3B Round Tube Die Set - 5/8" (2.25-180) .049" $115.00 *
100181 M3B Round Tube Die Set - 5/8" (3-180) .049" $135.00   
100182 M3B Round Tube Die Set - 3/4" (2.25-180) .058" $115.00 *
100183 M3B Round Tube Die Set - 3/4" (3-180) .058" $135.00 *
100186 M3B Round Tube Die Set - 3/4" (4.5-180) .058" $195.00   
100188 M3B Round Tube Die Set - 3/4" (5.5-180) .058" $220.00   
100189 M3B Round Tube Die Set - 7/8" (3-180) .058" $140.00 *
100191 M3B Round Tube Die Set - 7/8" (4.5-180) .058" $195.00   
100193 M3B Round Tube Die Set - 7/8" (5.5-180) .058" $220.00   
100194 M3B Round Tube Die Set - 1" (3-180) .058" $145.00 *
100195 M3B Round Tube Die Set - 1" (3.5-180) .058" $175.00 *
100197 M3B Round Tube Die Set - 1" (4.5-180) .058" $205.00 *
100199 M3B Round Tube Die Set - 1" (5.5-180) .058" $230.00   
100200 M3B Round Tube Die Set - 1 1/8" (3.5-180) .083" $175.00 *
100202 M3B Round Tube Die Set - 1 1/8" (4.5-180) .058" $215.00 *
100204 M3B Round Tube Die Set - 1 1/8" (5.5-180) .058" $240.00   
100206 M3B Round Tube Die Set - 1 1/8" (6.5-180) .058" $250.00   
100207 M3B Round Tube Die Set - 1 1/4" (3.5-180) .083" $175.00   
100209 M3B Round Tube Die Set - 1 1/4" (4.5-180) .058" $215.00 *
100211 M3B Round Tube Die Set - 1 1/4" (5.5-180) .058" $240.00   
100213 M3B Round Tube Die Set - 1 1/4" (6.5-180) .058" $250.00   
100215 M3B Round Tube Die Set - 1 3/8" (4.5-180) .095" $225.00 *
100217 M3B Round Tube Die Set - 1 3/8" (5.5-180) .065" $240.00 *
100219 M3B Round Tube Die Set - 1 3/8" (6.5-180) .065" $250.00   
100223 M3B Round Tube Die Set - 1 1/2" (4.5-180) .095" $225.00 *
100226 M3B Round Tube Die Set - 1 1/2" (5.5-180) .083" $240.00 *
100228 M3B Round Tube Die Set - 1 1/2" (6.5-180) .058" $250.00 *
100234 M3B Round Tube Die Set - 1 5/8" (5.5-180) .083" $250.00 *
100236 M3B Round Tube Die Set - 1 5/8" (6.5-180) .083" $260.00 *
100240 M3B Round Tube Die Set - 1 3/4" (5.5-180) .095" $260.00 *
100242 M3B Round Tube Die Set - 1 3/4" (6.5-180) .083" $275.00 *
100246 M3B Round Tube Die Set - 1 7/8" (6.5-180) .095" $295.00 *
100249 M3B Round Tube Die Set - 2" (6.5-180) .095" $295.00 *

Thanks for the research Kyota, I would like to try the thicker tube. I didn't know we were right on the borderline with that die. Knowing that, I would think the quality of the tube would be more important when operating on the borderline of the equipments intended use. I am gonna try another stick and see if it is better. What really confuses me is my friend uses the same bender and bends the same tube all the time with no problems. I see from your list that a 6.5" die can bend thinner tube yet. I will try to borrow a 6.5" die and see if the tube still kinks.

[freds40]

X2 on thickness. Try some .120 and it should be fine. .095 is a bit thin for my taste on bumpers as I have bent .120 wall 1.75 not easily, but it has happened.

[KYOTA]

yeah try heavier tube or the larger rad. die. Also I use white lithium grease (in spray can) for my follower dont know if that makes a difference tho, your not lubing the die are you? just the follower. good luck

[alwayzbroken [OP]]

yeah try heavier tube or the larger rad. die. Also I use white lithium grease (in spray can) for my follower dont know if that makes a difference tho, your not lubing the die are you? just the follower. good luck

I have been lubing everything since it started to kink. But only the follower at first when I noticed the kinks. What happens if you lube the die?

[KYOTA]

 manual says no lube on the die, but I dont see how it could slip with the sinch collar around the tube.

[Rockdiver]

Is the die right side up?   My m tech bender has a mark on top side      Lynn

[alwayzbroken [OP]]

Is the die right side up?   My m tech bender has a mark on top side      Lynn

I don't know about that. I do remember seeing that it was labeled with two different degrees. I think one side of the die had 3 degrees stamped in it and the other had 4 degrees on it. I don't know what that means.

[Rockdiver]

Mine has the size stamped on the top side .   Tears up the tube if put in upside down   I painted the top side so I dont do that again